CVE-2017-2850 in C1 Indoor HD Camera
Summary
by MITRE
In the web management interface in Foscam C1 Indoor HD cameras with application firmware 2.52.2.37, a specially crafted HTTP request can allow for a user to inject arbitrary characters in the pureftpd.passwd file during a username change, which in turn allows for bypassing chroot restrictions in the FTP server. An attacker can simply send an HTTP request to the device to trigger this vulnerability.
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Analysis
by VulDB Data Team • 12/09/2022
The CVE-2017-2850 vulnerability represents a critical security flaw in Foscam C1 Indoor HD cameras running firmware version 2.52.2.37, specifically within the web management interface's handling of user authentication and FTP server operations. This vulnerability falls under the category of insecure input handling and privilege escalation, with the potential for significant impact on network security. The flaw exists in the way the device processes HTTP requests related to username changes, creating a path for malicious actors to manipulate system files and bypass fundamental security restrictions.
The technical exploitation of this vulnerability occurs through a carefully crafted HTTP request that targets the web management interface of the camera. When a user attempts to change their username, the system fails to properly sanitize the input data before processing it for the pureftpd.passwd file modification. This inadequate input validation allows attackers to inject arbitrary characters into the password file, effectively manipulating the FTP server's authentication mechanism. The vulnerability is particularly concerning because it directly impacts the chroot restrictions that normally isolate the FTP server processes from the rest of the system, enabling attackers to gain unauthorized access to sensitive system resources.
The operational impact of CVE-2017-2850 extends beyond simple unauthorized access, as it provides attackers with the ability to bypass critical security controls that protect the device's file system and network communications. This vulnerability aligns with CWE-20, which describes improper input validation, and represents a classic example of how web application flaws can cascade into system-level security breaches. The attack vector is particularly dangerous because it requires no specialized tools or advanced knowledge beyond the ability to send HTTP requests, making it accessible to threat actors with minimal technical expertise. Once exploited, attackers can potentially access stored video footage, modify device configurations, or use the compromised camera as a pivot point for attacking other network devices.
This vulnerability demonstrates the importance of proper input sanitization and access control enforcement in embedded network devices, particularly those with web management interfaces. The flaw represents a failure in the principle of least privilege, where the FTP server's chroot restrictions can be bypassed through manipulation of user account data. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and credential access, specifically leveraging weak input validation to achieve unauthorized system access. Organizations should implement immediate mitigations including firmware updates, network segmentation, and monitoring for suspicious HTTP traffic patterns. The vulnerability also underscores the need for regular security assessments of IoT devices and the importance of maintaining up-to-date firmware to protect against known exploits that could compromise network security.